1. An active renal crystal clearance mechanism in rat and man
Benjamin A. Vervaet, Anja Verhulst, Simonne E. Dauwe, Marc E. De Broe, Patrick C. D'Haese 
Kidney International 
Volume 75, Issue 1, Pages (January 2009)
DOI: /ki
Copyright © 2009 International Society of Nephrology Terms and Conditions

2. Figure 1
Urinary biochemistry and nephrocalcinosis. (a) Urinary oxalate excretion showing the transient effect of EG administration with hyperoxaluria persisting until day 2 after arrest of EG administration. (b) Urinary pellet calcium shows clear crystalluria during EG administration only. (c) Renal crystal content during recovery after arrest of EG administration. Quantification of the amount of crystal-containing tubules/sites on Von Kossa-stained sections shows clearance of nephrocalcinosis. Data are presented as individual values (diamonds) and median (horizontal bars). Black diamonds represent the animals where phenotypical evaluation (Figure 2) was performed. Asterisk represents combined individual data of animals killed at days 1, 2, 3, and 4 during EG administration. # represents values of control animals of each group killed during and after the EG administration period. ∞ represents values of control animals of each group killed after arrest of EG administration. In the graphs, letters a–d represent P<0.05 versus control (Ctr), +2, +5, and +10, respectively, by Mann–Whitney U-test.
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Copyright © 2009 International Society of Nephrology Terms and Conditions

3. Figure 2
Frequency of phenotype. Images of serial sections stained with von Kossa (left) and PAS/PCNA (right), respectively. The amount of (a) normal tubules with crystals and (b) tubules with crystals adherent to regenerating cells decreases during recovery after arrest of EG administration. Concomitantly the amount of tubules with (c) crystals overgrown by the tubular epithelium and (g) the number of sites with interstitial crystals increases. (k) By day 25 only a few crystal-containing granulomas are found. (d) Crystals overgrown by young flattened epithelial cells, which most likely differentiate into (e) the polarized epithelia covering the crystals and presenting basement membrane deposition (e: PAS/PCNA, insert; f: Jones stain) and restoration of brush border (e: PAS/PCNA, insert). (g) Interstitial crystals either not (h) or already (i, j) being disintegrated in the subepithelial environment. (l) Cumulative summary of graphs ‘a’ to ‘k’. Concomitant with the decrease in renal crystals (Figure 1) the frequency of overgrown and interstitial crystals increases, reaching up to almost 90% by day 10. Of the few crystals left on day 25 only a minority are found in granulomas. Data are presented as mean (±s.d.) relative frequencies of the five phenotypes of three animals at time points +2, +5, and +10, and five animals at time point +25. In the graphs, letters a–c represent P<0.05 versus time point +2, +5, and +10, respectively, by χ2-test.
Kidney International  , 41-51DOI: ( /ki )
Copyright © 2009 International Society of Nephrology Terms and Conditions

4. Figure 2
Frequency of phenotype. Images of serial sections stained with von Kossa (left) and PAS/PCNA (right), respectively. The amount of (a) normal tubules with crystals and (b) tubules with crystals adherent to regenerating cells decreases during recovery after arrest of EG administration. Concomitantly the amount of tubules with (c) crystals overgrown by the tubular epithelium and (g) the number of sites with interstitial crystals increases. (k) By day 25 only a few crystal-containing granulomas are found. (d) Crystals overgrown by young flattened epithelial cells, which most likely differentiate into (e) the polarized epithelia covering the crystals and presenting basement membrane deposition (e: PAS/PCNA, insert; f: Jones stain) and restoration of brush border (e: PAS/PCNA, insert). (g) Interstitial crystals either not (h) or already (i, j) being disintegrated in the subepithelial environment. (l) Cumulative summary of graphs ‘a’ to ‘k’. Concomitant with the decrease in renal crystals (Figure 1) the frequency of overgrown and interstitial crystals increases, reaching up to almost 90% by day 10. Of the few crystals left on day 25 only a minority are found in granulomas. Data are presented as mean (±s.d.) relative frequencies of the five phenotypes of three animals at time points +2, +5, and +10, and five animals at time point +25. In the graphs, letters a–c represent P<0.05 versus time point +2, +5, and +10, respectively, by χ2-test.
Kidney International  , 41-51DOI: ( /ki )
Copyright © 2009 International Society of Nephrology Terms and Conditions

5. Figure 3
Morphology of crystals. Images of serial sections either stained with the Von Kossa method (outer left images in a, b, c, d, e; crystals are black) or prepared for SEM (right hand images). (a) Adhered crystals and (b) overgrown crystals show rather large intact crystal lattices. (c, d) Interstitial crystals either show smaller crystallites at their periphery (c, white arrows) or are completely scattered and interspersed with cellular material (d), suggesting crystal disintegration. (e) The surface of crystals in granulomatous structures has a microcrystalline appearance, as shown in the consecutive magnifications.
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Copyright © 2009 International Society of Nephrology Terms and Conditions

6. Figure 4
Inflammation. Relative percentage of the different crystal containing tubular phenotypes associated with (a) OX-1+ (CD45, common leukocyte antigen) and (b) ED-1+ (CD68, monocyte/macrophage marker) cells at the different time points after arrest of EG administration. Whereas the association of OX-1+ cells with crystal-containing tubules/sites and crystals increases with recovery time, the association with ED-1+ cells is moderate and transient during renal crystal clearance.
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Copyright © 2009 International Society of Nephrology Terms and Conditions

7. Figure 5
Frequency and examples of clear overgrowth structures in human kidney biopsies with nephrocalcinosis of different etiology. Owing to the extent of nephrocalcinosis and renal damage in the biopsies of primary hyperoxaluria no quantitative morphological data could be obtained.
Kidney International  , 41-51DOI: ( /ki )
Copyright © 2009 International Society of Nephrology Terms and Conditions